When using coaxial and twin lead probes, the GWR is sensitive to contamination and will therefore require regular cleaning. The Rosemount 5300 Series guided wave radar has a very high sensitivity and a single lead probe can be used to measure both level and interface and with this probe, the cleaning can be kept to a minimum – if required at all. Further, the 5300 features a function called “Signal Quality Metrics”, which continuously keeps track of the signal quality and possible contamination – and that way it is possible to predict possible maintenance/cleaning in good time before it becomes an issue. The “Signal Quality Metrics” can be used in level applications (not for level + interface).
Emulsion can be a challenge as it is a state which can vary from case to case and situation to situation: Generally, the GWR will measure the top of the emulsion layer, but when the emulsion is fully gradient, it will of course be impossible to detect. Our recommendation is to install the GWR at the part of the vessel where it is calmest, in order for the products to settle. One solution may be to install a stilling well. With a stilling well, the likeliness of contamination is much less than for twin lead- or coaxial- probes.
Hope this helps!
Not GWR, but I just wanted to mention there are specific temperature and Water cut sensors available from Rosemount. This one is with multi spot temperature and Water level sensor but you can get it without the temp sensor part. Normally used for net volume calculations in our Raptor Inventory Tank gauging systems connected to a 2410 tank hub but can also be open FF to host. There are special version for crude. It might be worth a look from a cost perspective if you have more than one vessel to equip. More about the sensor and the Raptor system following the link (If I made it properly..). www2.emersonprocess.com/.../Rosemount_765.aspx
Best Regards
Håkan Jubel, Rosemount Tank Gauging